Some lock assemblies include a housing and a plug that define respective pin chambers to receive pin pairs that respond to a key inserted in a keyway of the plug. When the correct key is inserted, the plug is rotatable relative to the housing to an unlocked position. The plug rotates an latch operating mechanism that is attached to the end of the plug with an end cap.
Some existing lock assemblies include end caps in the form of a mortise cam that is attached to the plug so that the plug moves the mortise cam between a locked position and an unlocked position to operate a latch. In some lock cylinders the mortise cam is attached to the lock cylinder using a screw. Other lock assemblies use end caps in the form of a cylinder that is attached to the plug to rotatably couple a driver bar to the plug. The driver bar extends from the plug to operate a latch to lock and unlock the door. Typically, the end cap is attached to the plug using a threaded connection between the cylinder and the plug. The plug further includes a spring-biased alignment pin that secures the end cap in a fixed rotational position relative to the plug so that the mortise cam or cylinder is fixed to the plug to rotate with the plug.
Since lock cylinder plugs are typically designed to support both types of end cap attachments, cylinder plug geometries are complicated and difficult to manufacture. In addition, the attachment features on the plug introduce weaknesses that can cause failure. Increased manufacturing time to assemble the end cap with the plug is also caused by the complicated and intricate interfaces created by the screwed and threaded connections. Therefore, additional improvements in the attachment of end caps to lock assemblies is needed.